Deep Water Trees
A lot of trees are suffering from the hot dry summer we experienced last year. Especially in unirrigated areas, soil became so dry that roots were lost. This has caused excessive browning and loss of needles on evergreen conifers. Typical lawn irrigation practices do not get enough water down deep enough for tree roots. Grass roots are very fibrous and intercept most of the water before it reaches tree roots. An extra deep irrigation every two weeks during August and September will improve tree health. Doubling or tripling the length of irrigation time twice a month will help get the water deeper into the soil. If you get excessive runoff when you run automatic sprinklers that long, run them through a cycle 2 or 3 times on the same day.
Sprinkler and drip tube hoses can be an effective way to get extra water to trees. Most of the water absorbing tree roots are in the area just inside and just outside of the outer branches. A drip or sprinkler hose can be placed in a circle around a tree and allowed to run several hours until the water reaches a foot deep.
Allen Wilson
Allen has been writing about gardening for over 30 years. He is a retired professor of Horticulture.